Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. 
|Bended thumb as example of hypermobility|
Hypermobility (also called double-jointedness, hypermobility syndrome or hyperlaxity) describes joints that stretch farther than is normal. For example, some hypermobile people can bend their thumbs backwards to their wrists, or bend their knee joints backwards. It can affect a single joint or multiple joints throughout the body.
Hypermobility generally results from one or more of the following:
- Misaligned joints
- Abnormally-shaped ends of one or more bones at a joint
- A Type 1 collagen defect (found in Ehlers-Danlos Syndrome, Marfan syndrome) results in weakened ligaments, muscles & tendons. This same defective process also results in weakened bones which may result in osteoporosis and fractures
- Abnormal joint proprioception (an impaired ability to determine where in space parts of the body are, and how stretched a joint is)
The condition tends to run in families, suggesting that there may be a genetic basis for at least some forms of hypermobility. The term double jointed is often used to describe hypermobility, however the name is a misnomer and is not to be taken literally, as an individual with hypermobility in a joint does not actually have two separate joints where others would have just the one.
Some people have hypermobility with no other symptoms or medical conditions. However, people with hypermobility syndrome may experience many difficulties. For example, their joints may be easily injured, and they may develop problems from muscle overuse (as muscles must work harder to compensate for the excessive weakness in the ligaments that support the joints).
Hypermobility may also be symptomatic of a serious medical condition, such as Ehlers-Danlos Syndrome, Marfan syndrome, rheumatoid arthritis, osteogenesis imperfecta, lupus, polio, down syndrome, morquio syndrome, cleidocranial dysostosis or myotonia congenita.
In addition, hypermobility has been associated with chronic fatigue syndrome and fibromyalgia.
Hypermobility syndrome (known by a variety of other names, including Benign Joint Hypermobility Syndrome) is generally considered to comprise hypermobility together with other symptoms, such as myalgia and arthralgia, and extra-articular features such as skin hyperextensibility and varicose veins. It affects more females than males.
The current diagnostic criteria for hypermobility syndrome are the Brighton criteria, which incorporates the Beighton score. Hypermobility syndrome is considered by many doctors expert in hypermobility (e.g. Professor Rodney Grahame) to be equivalent to the Hypermobile Type of Ehlers-Danlos Syndrome.
People with hypermobility syndrome may develop other conditions caused by their lax connective tissues. These conditions include
- Gastroesophageal Reflux Disease (GERD)
- Irritable Bowel Syndrome (IBS)
- Varicose Veins
- Flat feet, pronated feet, plantar fasciitis or sesamoiditis and unsupportive shoes
- Idiopathic scoliosis
- Joint instability causing frequent sprains, tendinitis, or bursitis when doing activities that would not affect the normal individual.
- Early-onset osteoarthritis
- There is evidence linking hypermobility syndrome to anxiety and depression. 
- Subluxations or dislocations, especially in the shoulder.
- Knee pain
- Back pain, prolapsed discs or spondylolisthesis
- Bruising easily
- Worsening of symptoms in cold weather
- Joints that make clicking noises
- Susceptibility to whiplash
- Temporomandibular Joint Syndrome also known as TMJ syndrome
- Increased nerve compression disorders (i.e. carpal tunnel syndrome)
- Mitral valve prolapse
- Uterine prolapse
It is important that the individual with hypermobility remain extremely fit - even more so than the average individual - to prevent recurrent injuries. Regular exercise and physical therapy or hydrotherapy can reduce symptoms of hypermobility, because strong muscles help to stabilize joints. These treatments can also help by stretching tight, overused muscles and ensuring that the person can use their full, hypermobile range of motion. Low-impact exercise such as Pilates is usually recommended for hypermobile people as it is less likely to cause injury than high-impact exercise or contact sports.
Moist hot packs can relieve the pain of aching joints and muscles. For some patients, ice packs also help to relieve pain.
Medications frequently used to reduce pain and inflammation caused by hypermobility include analgesics, anti-inflammatory drugs, and tricyclic antidepressants. Some people with hypermobility may benefit from other medications such as steroid injections or gabapentin, a drug originally used for treating epilepsy.
For many people with hypermobility, lifestyle changes decrease the severity of symptoms. For example:
- If writing is painful, people may be able to reduce the pain by typing.
- If typing is painful, they may try voice control software for their computer.
- They should avoid over-stretching the joints - stretching to one's maximum capabilities may result in injuries. Just because they are able to stretch much further, doesn't mean that it is a good idea.
- They should watch their posture to make sure they are standing or sitting up straight. Weakened ligaments & muscles contribute to poor posture which may result in numerous other medical conditions.
- Bracing to support weak joints may be helpful, but caution must be used not to weaken the joints further.
- Those who are overweight should lose weight. The extra weight puts additional stress on the already weakened ligaments, making them more susceptible to injury.
- Hypermobility & Fibromyalgia Support Site
- Oxford Journals: Rheumatology, Living with Hypermobility Syndrome
- Arthritis Research Campaign
- NHS Direct
- Cleveland Clinic Health System
- Joint Hypermobility Syndrome Review
- Sports Injury Bulletin
- Kids Physio
- The Disability Handbook on Arthritis
- Arthritis Research Campaign
- Association Between Joint Hypermobility Syndrome and Panic
- London Pain Consultants
- Hypermobility Syndrome Association
- Video of hypermobile person
- Cleveland Clinic Health System
- Journal of the American Orthopedic Association
Template:Diseases of the musculoskeletal system and connective tissue